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Convertible Top Control

Basic Description

The process of raising and lowering the convertible tops on most modern automobiles involves a series of complex and synchronized events coordinated by a microcontroller. The automotive market offers soft top convertibles and hard top convertibles employing different methodologies for the folding of the roof. Soft tops come in many different types, but most soft tops utilize the basic Z-frame mechanism. Convertible hard tops can be made from 1 to 5 independent panels that are folded one on top of each other and then retracted into the trunk space. Independent of the type of construction, a convertible utilizes several position sensors to monitor the movements of the convertible top while ensuring a safe operation that will not harm the occupants. Most modern top mechanisms will employ a series of hydraulic actuators. These are very compact hydraulics pumps, typically mounted in the trunk. A series of valves and solenoids control the hydraulic power to move each component correctly. The entire convertible system is generally monitored and controlled by an independent convertible control module. This module typically contains a microprocessor and employs CAN communications to communicate with other systems and receive information such as vehicle speed and user requests for top operation via the remote key fob. After receiving a request for operating the top and confirming that certain parameters are within their allowable limits, the convertible control module will initiate the sequence of events that are needed in order to close open or close the convertible top.

Fluid pressure sensors, temperature sensor, position sensors
DC brushless motors on hydraulic pump, DC brushed motor on top lock mechanism, solenoids used to control hydraulics
Data Communications
Typically CAN
Magna, Webasto, Valmet Automotive
For More Information
[1] Convertible, Wikipedia.
[2] Saab 9-3 Convertible - Cabriolet Soft-top System,
[3] Hardtop Convertible Model , YouTube, Oct. 1, 2010.
[4] 2010 BMW 328i Convertible Top Operation, YouTube, Feb. 18, 2012.
[5] Jaguar XK Convertible Top Operation, YouTube, July 10, 2013.
[6] 2014 Corvette Stingray, YouTube, Aug. 3, 2013.
[7] Soft-top Convertible Mechanism for Optimized Vertical Storage, YouTube, Aug. 29, 2013.
[8] A Look at the Top Operation of the 2015 Ford Mustang Convertible, YouTube, Feb. 26, 2014.